高压线工频电磁污染状况调查

Investigation of Power-frequency Electric and Magnetic Fields Distribution of High Voltage Overhead Power Lines

目的了解高压线及居民区工频电磁辐射污染状况。方法根据HJ/T24—1998《500kV超高压送变电工程电磁辐射环境影响评价技术规范》对距离高压线外边导线50m范围内不同距离处工频电场和磁场强度进行监测,同时对不同负荷条件下高压线两侧100m内(高压线电磁污染区)及200m外(高压线电磁场相对无污染区)居室内工频磁场强度进行监测。结果高压线工频电磁场强度随着距离增加快速衰减,工频磁场强度与电负荷、塔高、监测点高度及距离密切相关;高压线边导线外10m处工频电场强度最大,高压线边导线下工频磁场强度最大,76.5%监测值大于0.4μT,边导线外50m处17.6%的工频磁场强度大于0.4μT;高压线污染区居室内工频磁场强度远高于相对无污染区,所有相对无污染区的居室工频磁场强度均小于0.4μT,而污染区内62%的居室工频磁场强度大于0.4μT,高压线电磁污染区居室内的工频磁场强度高于相对无污染区(P<0.001);经多元回归分析,高压线电磁污染区居室内工频磁场强度与采样点距高压线距离和高度相关(P<0.001)。结论高压线两侧50m内的居室工频磁场强度与高压线电磁污染密切相关,建议高压线两侧50m内不宜建设学校、幼儿园、住宅和医院。

Objective To investigate environmental pollution of high voltage overhead power lines electromagnetic fields （EMF） of power-frequency. Methods Electric and magnetic fields of power-frequency from high power line were tested according to the Technical Regulations on Environmental Impact Assessment of Electromagnetic Radiation Produced by 500 k V Ultrahigh Voltage Transmission and Transfer Power Engineering （HJ/T 24-1998）, outdoor measurements were tested at area within 50 m of high power lines, indoor measurements were monitored at residences around （〈100m） and far from （〉200m） high power lines; measurements were tested at hours of relative higher and lower loads. Results Power frequency electric fields and magnetic fields decreased rapidly with distance from high power lines. Multiple regression showed that magnetic fields were closely associated with loads, height of tower, and height of measurement （P〈0.001）. Maximum electric fields were found at 10 m from high power line, and maximum magnetic fields were found just under the cable of high power line. Average residential magnetic fields were about 0.05- 0.10 uT in China. None of measurements at residences far from high power lines （〉200 m） were higher than 0.4 uT, whereas 62% measurements at residences within 100 m of high power liner were higher than 0.4 uT. It was statistically significant （P〈0.001）. Conclusion Residential power-frequency magnetic fields are associated with the proximity of high power lines. It is suggested that residences, schools, nursery school, and hospitals should not be located within 50m of high power lines.